The present invention relates to electrical safety circuits utilized in power tools and, more particularly, to an electrical safety device which has a disconnect relay that is energized when the power tool makes contact with a conductive material. The present invention also has a reset relay that is energized by a push button allowing the power tool to be quickly reactivated once there is no longer any contact between the power tool and the conductive material.
In modern construction, it is often necessary to provide access to power and communication lines that may be housed in metal raceways, pipes or other conductive materials found beneath floors constructed of various materials, such as concrete. Power tools are used to penetrate the floor above the conductive material. It is important that the power tool does not penetrate the conductive material, since this may result in numerous electrical hazards including harmful and possibly fatal electrical shocks to the equipment operator. Therefore, it is essential that the power tool is equipped with a safety device that discontinues equipment operation upon contact with any hidden conductive material.